Face a chin-up bar or a bar attached to a pulldown machine. If performing this stretch on a pulldown machine, put the pin at the end of the stack.
Grasp the bar with your hands spaced slightly wider than shoulder width.
Allow your body to hang from the bar (your feet can be on the floor). For a maximum stretch, allow the full weight of your body to hang from the bar. For a more relaxed stretch, support your weight by keeping your feet on the floor.
Hold for thirty seconds at the point of maximum stretch.
Repeat, if you like, with your hands either closer together or farther apart.